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Hopefully this will grow into a useful "How To"

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How to use tcpdump

How to use tcpdump

This is a quick tutorial to help find information quickly using tcpdump.  I'm not going to get into explaining everything just some quick commands to find what you are looking for. Capture HTTPS Traffic tcpdump -nnSX port 443 NOTE: You can use the same command to capture any traffic, just change the port 21:57:41.587391 IP 10.11.24.11.60394 > 146.88.138.28.443: Flags [S], seq 2618307083, win 29200, options [mss 1460,sackOK,TS val 1261029685 ecr 0,nop,wscale 7], length 0     0x
Test firewall not blocking traffic

Test firewall not blocking traffic

In the environment I work in we have multiple firewalls in a path so the likely of your traffic being blocked is high.  Most of us use to troubleshoot using telnet which has many many flaws and not a great method of testing but it was all we had. Here is an example of testing using telnet telnet 10.11.24.11:80 telnet: 10.11.24.11:80: Name or service not known 10.11.24.11:80: Unknown host The telnet results don't really give you anything to tell you if its successful or not.  The
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